Lead sharpener for draftsmen&#39;s pencils



w K O l m N 4 T T E 2 E N 0 E E 8 H V 7 m 6 Z 2 m. 7 m x 5 E E H s 2 -mmmm C. F. HAASE LEAD SHARPENER FOR DRAFTSMENS PENCILS Nov. 18, 1952 Flled May 23, 1951 Nov. 18, 1952 c. F. HAASE LEAD SHARPENER FOR DRAFTSMEINS PENCILS 2 SHEETS-SHEET 2 Filed May 23 1951 INZENTOR.

ATTOK/VEVAY Patented Nov. 18, 1952 LEAD SHARPENER FOR DRAF'ISMENS PENCILS Charles F. Haase, Milwaukee, Wis.

Application May 23, 1951, Serial No. 227,780

2 Claims.

This invention relates to improvements in lead sharpeners for draftsmens pencils.

Draftsmens pencils are of two types, namely, mechanical pencils, and ordinary wooden pencils. The lead of a draftsmans pencil must be frequently sharpened, and the method ordinarily used is to draw the point of the pencil lead across the face of a file or a similar abrasive surface. For various applications, different types of points are desired by draftsmen. For example, a sharp conical point may be needed for drawing fine lines, whereas a blunter point is more desirable for lettering work. For compass leads, a single bevel pointof predetermined length is required, while other drawing work may require a double beveled pencil point.

It is, of course, desirable to produce the re quired point with a minimum of grinding away of lead, so that the life of the lead is prolonged as much as possible. The sharpeners heretofore available have not been entirely satisfactory for a number of reasons. Many of the prior sharpeners continue to grind away lead as long as the pencil is held therein after the point is formed. Further, the conventional sharpeners do not form a point of predetermined length, nor can they be used to selectively form conical, or single, or double beveled points.

With the above in mind, it is a general object of the present invention to provide a lead sharpener which can form a selected type of point on a pencil with a minimum of grinding away of lead.

A further object of the invention is to provide an improved sharpener of the class described which can form a point of predetermined length on the pencil being sharpened, this feature making the improved sharpener well adapted for use in the sharpening of leads of certain types of compasses as well as of pencils.

A further more specific object of the invention is to provide an improved sharpener of the class described which can selectively form on a lead a conical or single or double bevel point of a selected degree of sharpness.

A further specific object of the invention is to provide an improved sharpener of the class described having an adjustable lead stop member for gauging the length of the lead point prior to the sharpening operation, the construction of the sharpener being such that the length of the lead after sharpening is substantially the same as the length of the gauged lead prior to sharpening.

A further object of the invention is to provide an improved sharpener of the class described having a movable pencil holder and having an electric motor driven rotary abrasive element, there being a switch in the electrical circuit for the motor, said switch being positioned for actuation by the pencil holder to start said motor upon movement of the holder to lead sharpening position.

A further specific object of the invention is to provide a pencil holder formed with a pair of pencil holding bores which are angularly offset from each other so that a pencil placed in one of said holes can be formed with a conical or double beveled chisel type point, and a pencil placed in the other of said bores can be formed with a single beveled point of the type used on compass leads.

A further object of the invention is to provide an improved sharpener of the class described wherein the pencil holder is provided with an axially rotatable collar which is adapted to frictionally receive an ordinary wooden pencil coaxially therewith, said collar being held against axial movement by said holder whereby a pencil held therein is free to rotate axially, but any axial movement thereof is resisted by frictional contact with the collar.

With the above and other objects in view, the invention consists of the improved lead sharpener and all of its parts and combinations, as set forth in the claims, and all equivalents thereof.

In the drawings accompanying and forming part of this specification, wherein is shown one complete embodiment of the preferred form of the invention, and wherein like characters of reference indicate the same parts in all of the views:

Fig. 1 is a side elevational view of the improved sharpener with parts being broken away and showing a compass pencil arm positioned in one of the bores of the pencil holder;

Fig. 2 is a plan view of the improved sharpener with the cover removed;

Fig. 3 is a front elevational view of the improved sharpener with the cover removed;

Fig. 4 is a vertical sectional view taken approximately along the line 4-4 of Fig. 2 and showing a pencil positioned in the holder bore through which the view is taken;

Fig. 5 is a view similar to Fig. 4 showing a modified form of pencil holder; and

Fig. 6 is an enlarged sectional plan view taken approximately along the line 66 of Fig. 5.

Referring more particularly to Fig. l, the nu meral I 0 indicates an L-shaped channeled frame, and the numeral H indicates an electric motor, the rear end of which is connected, as by screws I2, to the upstanding arm of the frame H], as

shown. A secondary frame I3, which may be formed of a sheet metal stamping, has a centrally apertured circular plate portion I4 which is attached by the screws I2 to the front end face of the motor II. The plate l4 has an upwardly projecting rectangular extension I5 which terminates in a horizontally forwardly extending flange l5. Projecting forwardly and downwardly from theside edges of the extension I5 are a.

pair of spaced parallel generally L-shaped verti-. cal plates I1 and I8.

A preferably cylindrical pencil holder i9 is formed at one end with a relatively short-axially. extending shaft 20, and is formed at its other end with a longer axially extending shaft 2 I. The pencil holder I9 is positioned between'thetplates I I and I8, and the shafts 2B and 2I are jourw The naled in suitable hearings in said plates. holder I9 is cut away, as at 22, to form a flat-face or shoulder 23. Formed on the upper edge of the plate. 11 is a. rec n ular or o a a ge. 4 1 wh c x nds h rizontall war l renhe uld r. 3. fm: olde St p. ws 5.; and- 26 re dedt rou h. he flan nd: jacent. t e p si ends hereo n rea am d to be engaged by the shoulder 23 to limit the rotative movement of thepencil holder 19.

A helicalgtorsion spring. 21 ;ext ends around the, shaftll between the. adjacent end of ;the,. hold er I 9 and :the plate. I8; said; spring having, .one end in engagement 'with a. screw ZBcarriedbythe adjacent'end of,.the holder I9, the other endof I the spring. engaging a a screw 2 9 carried by the, plate I8; The Spring 2lgurges.theholderldina.

clockwise direction as viewed in Fig. 1, to ,there-. by urge theshoulder. 23. into engagement. with the stopscrew. 25.

The. holder. I9 is formedwith a .pairof tapered.

dependingends of the plates "and I8 is a horizontal bar 34. Positioned below and in alignment with r the bore sous avertically adjustable stop screw 35 which is threaded through the bar 34 and whichmay be provided with a lock nut 36. Positioned-below and in alignment with the bore 3| is a similar stop screw S'Iwhich is thread d through the bar '34 and it'niay be provided with a lock nut 38.

Connected to the undersideof the flange I6, as by screws 39, is anormally open pushbuttlon type electrical switch lll from w'hich projects a depressible pin 4 I. The pencil holder I9 is formed in its periphery with a depression 42 which 'is preferably conical in shape and which is posi tioned-to receive the rounded tip of the pin 4| when the holder is in the normal position shown in Figs. 1 to 3. Theswitch Gilis connectedin series with the power line 43 of the electric motor II, and rotation of the holder I9 depresses the pin 4| to close the contacts of-said switch.

Removablyfixed totheshaftof themotor II is asleeve 44 whichisformedat one end with a radially outwardly projecting annularilangef45l Removably coaxially fixed to the flange 45, as by screws 46, is a disk 41 having an annular abrasive surface 48. A removable cover 49 has a cylindrical portion 50 of approximately the same diameter as the plate I3 and has an upwardly extending rectangular portion 5|. The upper wall of the cover 49 is formed with an aperture 52 through which projects the upper peripheral surface of the holder I 9 to expose the upper ends of thebores 30.and3l.

When it is desired to put a single beveled point one compass pencil lead such as that in the pencil arm .33 of Fig. 1, the arm is inserted in the bore '39, as shown. The arm 33 is then pressed downwardly so that the lead holding mechanism releases the lead 53 and permits said lead to drop byugravity int contact with the stop screw 35. Upon releasing the downward pressure on the arm. 33-;the lead gripping mechanism tightens about the lead 53 as before. If the lead holding meche i eis .1 21319. qt wmi pt ne pe h lead is advanced.int eontact with the stop screw iwbil the rmfifir s e'etedi th b l 3-. h tep cr r 5% curat l gauges the t the 2 lih ch Pr ect e t a 3 a said stop screw is adj ustably positioned so that; elei et -i ea i 3s ai ed e yi t e act lengthrequired b y.the compass to matchthe pencil pointlwitlr that of the needleon the other arm of the compass.

Wi h Pe ci rm. iz ee ne i ebme 39, th' fupperend ofsaidarmis drawn to the left, as viewed. in. 1,- to rotate the pencil d I 9- i lfibi t re o w se r ti n n l the shoulder 23; abuts.th e stop screw 25, This rotation rotates the depressiondgfaway from.

the pin 4i of the vswitch 49.; and 1 depresses said 9 se he sweet id i ch; This causes 1 the motor I to ro tate. the disk 41 i The dc:

scribedifotationi of-the pencil ;holder I9 also swings the lead 53Jto. the dotand dash line posi tionof l,- and it willbe noted that when the.

lead is so positionedthe abrasive surfacefififorms a sing lejbevei ompa stype oin nthe ead. withoutshortening the gauged length of the.

lead f e t p ew. 61mm o at the. l ad 53 cannot be swung beyond the dot anddash line position of Fig, l, and-therefore said lead cannot be groundaway any more than that which is. necessary to produce the desired bevel on the gauged-length of lead Upon releasingthe compassarm 33, thespring. Z'kreturns the holder I9 to its n'ormal position, and the pin 4.! again.

Fig. 4;'tl 1e tip of-the pencil is placed in the bore 3 I, The lead 5- 4;is thenreleased or. advanced'intof contact with the stop screw, 31, andthe upper end of the pencil is drawn. tothe left to rotate the holdenl 9-in a counterclockwise.direction and bring the shoulder 23 ;into contact with the'stop' screw.25. The stopscrew 3leaccurately gauges the length of thelead 54, and, as previously described, rotation of the holder I9 away fromits. normal position. actuates the switch as and" causes. thenmotor tofrotate'jth e disk 41. The de.- scribedirotat ion of theholder l9 swings thelead 5l to' the dot and dashjine position of Fig. '4. and itwill e noted'that in this position theleadfil at -ei bt ielilie li fiie lerefi le t he rf e.

48 than the lead 53 in the dot and dash line position of Fig. 1. While the lead 54 is in contact with the abrasive surface 48, the pencil 32 may be axially rotated in the bore 33 to form a conical point on the tip of the lead 54.

When a double beveled chisel type point is desired on the lead 54, the pencil 32, instead of being axially rotated while in contact with the abrasive surface 48, is held against axial rotation. After a bevelled surface is formed on the lead, the holder I9 is returned to the normal position shown in Fig. 4. While the lead 54 is out of contact with the abrasive 48, the pencil 32 is rotated 180 degrees, and the lead 54 is again brought into contact with the abrasive surface 48 to form the second bevel surface on the lead. If a somewhat blunter point is desired, the stop screw 26 may be advanced downwardly so that the lead 54 engages the surface 48 at a smaller angle. Thus, a frusto-conical point can be formed on a pencil instead of a truly conical point.

Fig. 5 shows a modified form of pencil holder I9 which is similar in all respects to the holder l9 except that it is adapted to receive a conventional wooden pencil 52. The holder I9 is formed with a diametrically extending bore portion 55 having a diameter approximately equal to the diameter of a pencil 62. The bore 55 is formed at its lower end with a portion of enlarged diameter 56, and positioned in the portion 55 is a coaxial split collar 57 which is freely rotatable axially. The collar 51 is held in the portion 55 by a retaining plate 58 which is formed with an aperture 59 having a diameter approximately equal to that of the pencil 62. The retaining plate 58 is attached to the holder 19 by screws 50. A C-shaped spring 6| surrounds the split collar 51 to cause the latter to snugly frictionally engage the pencil 52 when the latter is inserted through the bore 55, collar 57 and aperture 59. The frictional engagement of the collar 57 with the pencil 62 resists axial movement of the pencil, but since the collar 57 is free to rotate in the bore portion 56, axial rotation of the pencil E2 is permitted.

In operation, the pencil 62 is pushed downwardly through the holder I 9 as shown, and into contact with the lead stop 34'. The upper end of the pencil 62 is then drawn to the left in the same manner as the pencil 32 of Fig. 4, to move the tip of the pencil into contact with the rotating abrasive 48' and to move the shoulder 23 into contact with the stop screw 26. The pencil 62 is then axially rotated while in contact with the abrasive surface 48' to form a conical point on said pencil by grinding away both the wood and the lead thereof. As was true with the preferred form of the invention the desired point is formed on the pencil without shortening the lead thereof. Only enough of the pencil is ground away to form the desired point.

While it is preferred to use a motor driven abrasive disk, the improved sharpener has utility whether or not the abrasive member is movably mounted.

Various other changes and modifications may be made without departing from the spirit of the invention, and all of such changes are contemplated as may come within the scope of the claims.

What I claim as the invention is:

1. In a pencil sharpener: an electrically driven movable abrasive member having a power circuit; a movably mounted pencil holder adjacent said abrasive member, said holder being adapted to hold a pencil to be sharpened and said holder being movable between a normal position wherein a pencil held thereby is spaced from the abrasive member and a sharpening position wherein the pencil is in abrading contact with the abrasive member; spring means normally holding said holder in said normal position; a stop member mounted adjacent said holder and positioned for engagement by the pointed end of a pencil in said holder when the holder is in normal position; and an electrical switch in the power circuit positioned for actuation by said holder upon movement of the latter to sharpening position.

2. In a pencil sharpener: an electrically driven movable abrasive member having a power circuit; a pivotally mounted pencil holder adjacent said abrasive member, said holder being adapted to hold a pencil to be sharpened and said holder being movable on its pivot axis between a normal position wherein a pencil held thereby is spaced from the abrasive member and a sharpening position wherein the pencil is in abrading contact with the abrasive member; spring means normally holding said holder in said normal position; a stop member mounted adjacent said holder and positioned for engagement by the pointed end of a pencil in said holder when the holder is in normal position; abutment means on said pencil holder; and an electrical switch in the power circuit positioned for engagement by said holder abutment means upon movement of the holder to sharpening position.

CHARLES E. HAASE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 792,785 OI-Ioro June 20, 1905 995,764 Bertram June 20, 1911 997,741 Rolle July 11, 1911 2,243,490 Walker May 27, 1941 FOREIGN PATENTS Number Country Date 626,744 Great Britain July 20, 1949 

